Through the TAACF screening program sponsored by NIAID, naturally occurring anti-HIV agent (+)-Calanolide A was found to be active against Mycobacterium tuberculosis. It is the first compound identified to possess anti-mycobacterial and antiretroviral activities against both HIV and TB. Therefore, (+)-Calanolide A may be a powerful agent to treat patients infected by these two pathogens and/or a useful chemoprophylactic agent for TB in HIV-infected people or vice versa. (+)-Calanolide A is currently undergoing Phase II clinical trials for anti-HIV efficacy. It is the objective of this SBIR Phase I program to further evaluate the anti-TB properties of (+)-Calanolide A to determine if it would be a viable anti-TB drug candidate and be moved forward into clinical trials for TB infection. An IND application for this purpose is anticipated to be filed with the FDA in the SBIR Phase II period if results are promising and clinical trials for TB efficacy will be initiated in the SBIR Phase III program. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE